The newest addition to the Volumetric Galaxy Pack is an Additive Star shader which is pretty much what it sounds like. It additively renders stars as point-like objects (though they are all quads).
Texture
Here’s where you attach your particle texture in case you would like to use something other than the default supplied in the Demo scene.
GlobalParticleSize
This setting is the overall multiplier which controls the size of all star particles.
Default: 0.6